"Frank Thomas" wrote in
:

Hi Troops!
Is there a substitution for a 300B vacuum tube. I really can not
afford a price tag of $134.00 and up. I am on a very fixed income.
There must be a less expensive and better way to go.
Thank you in advance,
Frank Thomas

There is only one direct substitute for a 300B(or 300A), and that is the
STC4300A, but it is even rarer and more expensive. The closest "common"
USA tube is the "50" but it is lower powered and a different filament
voltage. There is a closer British tube, the DA30 (which is a larger
PX25) but on a different base, and rare and expensive. One of the
Russian makers used to have a low mu variant of the 811 which was cheap
as chips - dunno if it still exists. There are a number of elcheapo
Chinese and Russian 300B copies. M